This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 10-009907, filed Jan. 21, 1998, the entire contents of which are incorporated herein by reference.
The present invention relates to a digital information recording/playback system which allows the user to create a menu corresponding to recorded contents, and an information recording.medium used in this system.
In particular, the present invention relates to a digital information recording/playback system which has a function of supporting the user to create a visual menu that partially uses .actual recorded contents (a still picture, a short movie, or the like), and an information recording medium used in this system.
In recent years, systems for playing back the contents of optical discs that have recorded video (moving picture) data, audio data, and the like have been developed, and have prevailed for the purpose of playing back movie software, karaoke, and so on like LDs (laser discs), video CDs (video compact discs), and the like.
Among such systems, a DVD (Digital Versatile Disc) standard that uses MPEG2 (Moving Picture Experts Group) international standard, and adopts an audio compression scheme such as AC-3 (digital audio compression) or the like has been proposed. The DVD standard includes read-only DVD video (or DVD-ROM), write-once DVD-R, and erasable/rewritable DVD-RW (or DVD-RAM).
The DVD video standard supports MPEG2 as a movie compression scheme, and AC3 audio and MPEG audio in addition to linear PCM as an audio recording scheme, in accordance with MPEG2 system layer. Furthermore, this DVD video standard is configured by appending sub-picture data for superimposed dialogs obtained by runlength-compressing bitmap data, and control data (navigation data) for playback control such as fastforwarding, rewinding, data search, and the like. Also, this standard supports ISO9660 and UDF Bridge format to allow a computer to read data.
An optical disc currently used as a DVD video (DVD-ROM) disc is a single-sided, single-layered 12-cm disc, which has a storage size of around 4.7 GB (gigabytes). A single-sided, double-layered disc has a storage size of around 9.5 GB, and a double-sided, double-layered disc allows large size recording of around 18 GB(when a laser having a wavelength of 650 nm is used to read).
On the other hand, an optical disc currently used as a DVD-RW (DVD-RAM) disc is a 12-cm disc, which has a storage size of around 2.6 GB (gigabytes) in case of a single-sided disc, and a storage size of 5.2 GB in case of a double-sided disc. Currently available DVD-RAM optical discs have a smaller storage size than DVD-ROM discs of equivalent size. However, technical developments for increasing the DVD-RAM disc storage size are being incessantly made, and DVD-RAM discs having a storage size of 4.7 GB or more per side will definitely become commercially available in the near future.
In the DVD video standard, a video manager menu (VMG menu) and video title set menu (VTS menu) are prepared as disc search menu pictures for contents providers (companies that produce contents, i.e., titles recorded on DVD discs).
A DVD video disc records video data (main picture) including video (moving picture) data as principal part of the recorded contents, and sub-picture data including auxiliary information such as superimposed dialogs and the like. The VMG menu or VTS menu is formed by some video data (still picture or short movie), and buttons (visual markers used by the user to select a selection item in the menu) using sub-picture data.
In this menu, a menu background and menu selection items are displayed by a still picture of main picture data, and a specific portion of sub-picture data is emphasized and displayed in a predetermined color, so that the user can visually recognize a specific menu selection item. The emphasized display portion using the sub-picture data serves as a button. The user can select a desired selection item using the button.
An example of a menu in DVD video will be explained below. Assume a menu for a single movie title divided into five chapters. In this case, five mini pictures obtained by reducing still pictures of starting portions of the respective chapters are output onto a single menu screen. A button is formed by a frame that fringes one of the five mini screens in a specific color (e.g., green). This green button frame can move on the menu by operating cursor keys of a remote controller of a DVD video player.
When the user wants to play back the movie from chapter 3, he or she moves the green button frame to a position where the frame surrounds the mini picture of chapter 3 by operating cursors. When the user then presses an enter button on the remote controller, the color of the button frame that surrounds the mini picture of chapter 3 changes from green to another color (e.g., red), and the user can confirm that selection of chapter 3 has been settled. At the same time, the DVD player searches for the recorded position of chapter 3, and starts video playback from chapter 3.
The aforementioned chapter search can be implemented by the visual menu that uses the main picture background and sub-picture button. That is, when a plurality of dedicated menu pictures (mini pictures described above:) obtained by adding a sub-picture button to normal video data are prepared, the user can play back the scene of the selected chapter by selecting the button.
However, a title creator must create all the dedicated menu pictures by himself or herself. In order to specially create such menu pictures (background picture, selection item pictures corresponding to the mini pictures), elaborate edit processes are required. However, it is difficult for the users of home-use DVD video recorders to perform such elaborate edit processes (which are complicated and troublesome, and are too much for elder or underage users).
In case of read-only DVD video, since the number of recorded titles remains the same, a menu need not be changed once it is created. However, when the number of recorded titles increases/decreases like in a DVD video recorder (DVD-RAM or DVD-RW) that can erase and rewrite data more than once, every time the number of titles changes, the entire menu screen must often be re-created. Such menu re-creation (or modification of the already created menu) is also troublesome for general users.
It is an object of the present invention to provide a digital information recording/playback system which allows the user to create a menu corresponding to the recorded contents, and an information recording medium used in this system.
In order to achieve the above object, a digital information recording/playback system of the present invention uses at least thumbnail picture control information as control information upon recording/playing back video data and the control information. At this time, the thumbnail picture control information includes information for generating a thumbnail picture generated based on contents of the video data, and information for using the generated thumbnail picture in a menu corresponding to the contents of the video data.
Also, in order to achieve the above object, a digital information recording medium of the present invention, which records video data and control information, includes at least thumbnail picture control information as the control information; and the thumbnail picture information includes information for generating a thumbnail picture generated based on contents of the video data, and information for using the generated thumbnail picture in a menu corresponding to the contents of the video data.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.